// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_RENDERER_P2P_SOCKET_CLIENT_IMPL_H_
#define CONTENT_RENDERER_P2P_SOCKET_CLIENT_IMPL_H_

#include <stdint.h>

#include <vector>

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "content/common/p2p_socket_type.h"
#include "content/renderer/p2p/socket_client.h"
#include "net/base/ip_endpoint.h"

namespace base {
class SingleThreadTaskRunner;
class TimeTicks;
} // namespace base

namespace content {

class P2PSocketDispatcher;

// P2P socket that routes all calls over IPC.
//
// The object runs on two threads: IPC thread and delegate thread. The
// IPC thread is used to interact with P2PSocketDispatcher. All
// callbacks to the user of this class are called on the delegate
// thread which is specified in Init().
class P2PSocketClientImpl : public P2PSocketClient {
public:
    explicit P2PSocketClientImpl(P2PSocketDispatcher* dispatcher);

    // Initialize socket of the specified |type| and connected to the
    // specified |address|. |address| matters only when |type| is set to
    // P2P_SOCKET_TCP_CLIENT.
    virtual void Init(P2PSocketType type,
        const net::IPEndPoint& local_address,
        uint16_t min_port,
        uint16_t max_port,
        const P2PHostAndIPEndPoint& remote_address,
        P2PSocketClientDelegate* delegate);

    // Send the |data| to the |address| using Differentiated Services Code Point
    // |dscp|. Return value is the unique packet_id for this packet.
    uint64_t Send(const net::IPEndPoint& address,
        const std::vector<char>& data,
        const rtc::PacketOptions& options) override;

    // Setting socket options.
    void SetOption(P2PSocketOption option, int value) override;

    // Must be called before the socket is destroyed. The delegate may
    // not be called after |closed_task| is executed.
    void Close() override;

    int GetSocketID() const override;

    void SetDelegate(P2PSocketClientDelegate* delegate) override;

private:
    enum State {
        STATE_UNINITIALIZED,
        STATE_OPENING,
        STATE_OPEN,
        STATE_CLOSED,
        STATE_ERROR,
    };

    friend class P2PSocketDispatcher;

    ~P2PSocketClientImpl() override;

    // Message handlers that run on IPC thread.
    void OnSocketCreated(const net::IPEndPoint& local_address,
        const net::IPEndPoint& remote_address);
    void OnIncomingTcpConnection(const net::IPEndPoint& address);
    void OnSendComplete(const P2PSendPacketMetrics& send_metrics);
    void OnError();
    void OnDataReceived(const net::IPEndPoint& address,
        const std::vector<char>& data,
        const base::TimeTicks& timestamp);

    // Proxy methods that deliver messages to the delegate thread.
    void DeliverOnSocketCreated(const net::IPEndPoint& local_address,
        const net::IPEndPoint& remote_address);
    void DeliverOnIncomingTcpConnection(
        const net::IPEndPoint& address,
        scoped_refptr<P2PSocketClient> new_client);
    void DeliverOnSendComplete(const P2PSendPacketMetrics& send_metrics);
    void DeliverOnError();
    void DeliverOnDataReceived(const net::IPEndPoint& address,
        const std::vector<char>& data,
        const base::TimeTicks& timestamp);

    // Helper function to be called by Send to handle different threading
    // condition.
    void SendWithPacketId(const net::IPEndPoint& address,
        const std::vector<char>& data,
        const rtc::PacketOptions& options,
        uint64_t packet_id);

    // Scheduled on the IPC thread to finish initialization.
    void DoInit(P2PSocketType type,
        const net::IPEndPoint& local_address,
        uint16_t min_port,
        uint16_t max_port,
        const P2PHostAndIPEndPoint& remote_address);

    // Scheduled on the IPC thread to finish closing the connection.
    void DoClose();

    // Called by the dispatcher when it is destroyed.
    void Detach();

    P2PSocketDispatcher* dispatcher_;
    scoped_refptr<base::SingleThreadTaskRunner> ipc_task_runner_;
    scoped_refptr<base::SingleThreadTaskRunner> delegate_task_runner_;
    int socket_id_;
    P2PSocketClientDelegate* delegate_;
    State state_;

    // These two fields are used to identify packets for tracing.
    uint32_t random_socket_id_;
    uint32_t next_packet_id_;

    DISALLOW_COPY_AND_ASSIGN(P2PSocketClientImpl);
};

} // namespace content

#endif // CONTENT_RENDERER_P2P_SOCKET_CLIENT_IMPL_H_
